Clock crystal



Nov. 20, 1928.

L. STERN CLOCK CRYSTAL Filed Dec. 13, 1927 INVENTOR Lou/s Srernv ,0 ;WM W

ATTORNEYS Patented Nov. 20, 1928. I

gLpUN v PA I OFFICE.

I LOUIS STERN, or WOODMERE, new YoRK, AssIGnoR TO 'rnn 1m LUXE GLGCK a zero. 00., me, on NEW YoRK, N. Y., A CORPORATION or new YORK.

CLOCK CRYSTAL.

Application filed December 13, 1927. Serial 110.23.),657.

The main objects of the present invention are to provide a clock crystal which is substantially non-breakable, which is inexpensive to manufacture, which may be easily and securely fastened in position, which does not require any high degree of accuracy as to dimensions or the forming of any bezel engaging edge, and which may be employed as a close-fitting cover for such parts of the clock face as may be present outside of the clock dial. I I

In carrying out my inventionl preferably form the crystal of celluloid or any other similar transparent substantially non-breakable and inexpensive material. The crystal is provided with a. center .portion which may conform in shape to the shape of the dial and which is spaced from the dial to a distance sufficient to permit the free movement of the hands. In a separate plane from this center portion is an annular marginal or peripheral portionwhich may be clamped or otherwise rigidly secured directly to or in direct contact with a corresponding portion of the clock face outside of the dial.

Between this center portionand the outer or marginal portionis a wall integral with both of said portions and serving to connect and space them to the desired'distance. This wall preferably follows the contour of the dial and holds the center portion of the -crys-' tal at a distance above the dial'to permit the movement of the hands.

In the accompanying 1 drawings I have illustrated certain embodiments of my invention, but it will of course be understood that various other forms may be designed within the scope of my invention, particularly so far. as concerns the forming of'the crystal in accordance with the relative shapes and sizes of the clock face and'dial thereon.

- In. these drawings: i Fig. l is a front view of a clock having a crystal constructed in accordance with my invention;

Fig. 2 is a side elevation, the front portion I of the clock case being in section a Fig. 3 is a front view showing another form; v

Fig. 4 is a central longitudinal section; Fig. 5 is a perspective view of the crystal snown in Figs. 3 and 4;

Fig. 6 is a front view of a third form; and

Fig. 7 is a section through the form shown in, Fig. 6.

In the construction shown in Figs. 1 and the works of the clock are mounted in a casing 10 which is secured to the rear side of a front wall which may be of metal or any other suitable material. The lower portion of this wall serves as a supporting bracket 11, while the front of the body portion 12 has printed, embossed or otherwise formed thereon the annular row of numerals forming the clock dial. These numerals are shown as being formed on an annular raised portion 13. The arbor of the clock projects through the center of the dial and the hands 14 are mounted on the front of the arbor and in proper position in respect to the dial.

In my improved construction there is provided a crystal of celluloid or any similar transparent non-breakable materia This includes a center portion 15 of substantially the same diameter as the nui'neral bearing portion 13-constituting the clock dial. This center portion may be either flator slightly convex as desired. Around the periphery of this center portion 15 is awall 16 which is of substantially cylindrical form and which serves to space the center portion 15 to the desired distance from the 01001: face. The inner edge of the wall 16 is formed integral with a flat marginal portion 17 which lies in close contact with the clock face out-' side of the dial. This outer marginal por tion lies in a plane substantially parallel to the plane of the center portion 15, but is spaced therefrom to a distance dependent uponthe height of the wall 16. This marginal portion is secured directly to the clock face by any suitable form of clamping means. As shown, there is an annular clamping menr ber 18 which may be made of an internal di ameter substantially equal to the diameter of the wall 16 and an external diameter substantially equal to the outside diameter of the marginal portion 1"? of the crystal. This annular member 18 may have any suitable form of ornamentation embossed or 0th erwise formed thereon. The clamping screws 19 may go directly through this annular member and through the marginal portion 17 into the clock face so as to secure the thrc parts together.

In Figs. 3, a and 5 I have'shown a con struction in which the casing 10 for the works is of the usual cylindrical form with the front wall 12 secured thereto and carrying the dial. This wall 12 is shown as being circular and of the same diameter as the easing 10, whereas the dial is shown as substantially square. In this arrangement the center portion 15 of the crystal may also be substantially square while the face as a whole is circular. The flat annular portion 17 encircling the dial is secured to the clock face by screws 19. The casing with the crystal secured thereto may be mounted in any suitable form of clock case which will cover all portions of the clocl: face except the dial. Merely for purposes of illustration I have shown a rectangular clock case 20 having a cylindrical opening in the rear into which the works casing 10" may be in erted. The front wall of the clock case has an aperture 21 which is substantially square and encircling this is an inwardly extendin wall 22 against which the portion of the cloc face and crystal outside of the dial may engage. The unnular wall 16 which en 'rcles tne'center or dial covering portion may be of a height either lesser or greater than the thickness of the wall 22 depending upon the nature and material of the clock case 20.

Although it is preferable that the center p rtion of the crystal be of a form corresponding to that of the dial, it is not essential so far as my particular invention is concorned.

In Figs. 6 and 7 I have shown a wall 12 which may constitute the clocl: face and secured to or form a part of any suitable clock case. It has a central aperture for the main hand carrying arbor. This clock face is shown as substantially square, while the dial 13 is shown of octagon shape. The crystal has a center portion 15 which may be either so; re or octagonal, but is shown as square. The peripheral wall 16 spaces this center portion above the clock face, while the marginal portion 1'7 is made comparatively nar row and may be secured directly to the clock face by the screws 19 at the corners.

In each of the forms illustratedthe wall 16, 16, or 16" serves to define the spacing of the center of the crystal above the clock face. This a continuous wall extending around the dial. In describing it as annular I do not use that term limiting the wall to a circular one but include within the term also a wall following an elliptical, square, he):- agonal. or any other desired form or shape of dial. or clock face. In the same way the tall 17 17, or 1'?" directly contacts with the clock face and may be considered as annular even though it may have other than circular inner and outer edges and may be variable in width, as for instance as shown in Fig. 5.

day of December, 1927.

The walls 17, 17- and 17 preferably directly contact with the clock face, butthis is not essential for they may be secured closely adjacent to the clock face, but not directly thereto. The annular wall 16, 16 or 16" may extend substantially at right angles to the plane of the clock face, but preferably merges into the center and marginal portions by curved intermediate portions which facilitate the moulding of the crystal. Obviously this connecting and spacing wall between the center and margin might be inclined, that is disposedat any desired angle other than a right angle to the clock face.

In using the term celluloid I do not wish to be restricted to any particular composition or material as there are various analogous materials which are substantially nonbreakable and sufiiciently transparent for the present invention. I desire to include all such equivalents of celluloid under that term. Having thus described my invention what I claim as new and desire to secure by Let ters Patent is: I

. In combination a clock face having a the latter to the annular portion of said clock 10o face.

2. In combination a clock face having a dial, a crystal having a center portion, a

peripheral wall and a marginal portion, said marginal portion being substantially paral- 1H5 lel to and spaced from said center portion by said wall, and means for securing said marginal portion directly to said clock face outside of said dial.

3. In combination a clock face having a dial, a crystal having a center portion, a peripheral wall and a marginal portion, said marginal portion being substantially parallel to and spaced from said center portion by said walls, means for securing said marginal portion directly to said clock face outside of said dial, and an annular wall in front of and concealing said marginal portion and having its inner edge disposed closely adjacent to the peripheral wall of said crystal.

Si ned at 1107 Broadway in the county of New York, and State of New York, this 10th llu 

